动态绑定方法一：动态绑定数据库中的字段。
SqlConnection conn = UtilitySqlClass.OperateDataBase.ReturnConn();
string strSQL = "select * from CompanyType";SqlDataAdapter ada = new SqlDataAdapter(strSQL, conn);DataSet ds = new DataSet();ada.Fill(ds, "CompanyType");DropDownList1.DataSource = ds.Tables["CompanyType"].DefaultView;DropDownList1.DataValueField = ds.Tables["CompanyType"].Columns[1].ColumnName;DropDownList1.DataTextField = ds.Tables["CompanyType"].Columns[1].ColumnName;DropDownList1.DataBind();ds.Dispose();
动态绑定方法二：利用DropDownList.Items.Add方法。
protected void Page_Load(object sender, EventArgs e)
{ if (!IsPostBack){ SqlConnection conn = UtilitySqlClass.OperateDataBase.ReturnConn();try{ conn.Open();this.DropDownList1.Items.Add("");string strSQL = "select CompanyType from CompanyType";SqlCommand com = new SqlCommand(strSQL, conn);SqlDataReader dr = com.ExecuteReader();while (dr.Read()){ this.DropDownList1.Items.Add(dr["CompanyType"].ToString());}}catch (Exception ex){ Response.Write("<scirpt>alert('" + ex.Message.ToString() + "')</script>");}finally{ conn.Close();}}}第一种方法：
string ConnString = ConfigurationSettings.AppSettings["ConnectionString"]; //创建一个SqlConnection SqlConnection Conn = new SqlConnection( ConnString );string SQL_Select = "select id, ItemName from DDLItem order by id desc";
//构造一个SqlDataAdapter
SqlDataAdapter myAdapter = new SqlDataAdapter( SQL_Select, Conn);
//开始读取数据
Conn.Open();
DataSet dataSet = new DataSet();
myAdapter.Fill( dataSet,"Table1" );
Conn.Close();
//开始绑定DropDownList
//指定DropDownList使用的数据源
DropDownList1.DataSource = dataSet.Tables["Table1"].DefaultView;
//指定DropDownList使用的表里的那些字段
DropDownList1.DataTextField = "ItemName"; //dropdownlist的Text的字段
DropDownList1.DataValueField = "id";//dropdownlist的Value的字段
DropDownList1.DataBind();
第二种方法： con.Open(); SqlCommand cmd = new SqlCommand(strSql,con); SqlDataReader dr = cmd.ExecuteReader(); while (dr.Read()) { DropDownList1.Items.Add(new ListItem(dr["status"].ToString(), dr["status_Id"].ToString())); }